Process of making sulfuric acid.



0. PEOELSS.

PROCESS OF MAKING SULPURIG ACID.

APPLICATION FILED DEC. 11, 190B.

. 963,175. Patented July 5,1910.

wi/liywoow .JWM, W

OTTO PB OELSS, OF KANSAS CITY, MISSOURI.

PROCESS-"OF MAKING SULFUR'IC ACID.

Specification of Letters Patent.

Patented July 5, 1910.

Application filed December 11, 1908. Serial No. 467,087.

. the following is a s cification.

This invention re ates to the manufacture concentration of sulfuric acid, and to th1s end embodies a certain process and means whereby to efi'ect the result with a minimum expenditure of fuel and labor, as fully set forth hereinafter and illustrated in the accompanying drawing which shows in sectional elevation one form of apparatus which may be employed. In the said apparatus there are three in dependent chambers X, X, XZwhich may be in independent towers, as shown'in the drawin or within a single structure in which t ey are separated by suitable partitions, andin said'chambersis arranged in any manner which may be found most suitable masses of'refractory material, as for instance chemical brick, the arrangement corresponding to such as is usually employed in what are known'as Glover towers.

Two of the chambers X','X are practi- 36 'cally identical in their characteristics, and

both of these chambers communicate through suitable conduits or pipes D with what is herein termed the intermediate chamber X, each of the said conduits being provided with a valve D. i

By means of suitable bonding material the lining of both of the chambers X, X

'may be arranged in such a manner that neither hot concentrated acid nor thehot gases will be able to destroy the lining.

For convenience I term the chambers X, X the concentrating chambers, or chambers of the concentrating means, and the chamber X the intermediate or mixing and coolin chamber without however intending to limit the construction to any particular arralifiement of the chambers except such as w' permit gases from either or both of the chambers X, X to be carried to the other chamber.

Each of the concentratin provided with means where y it may be supplied with burner gases, or sulfur dioxid, from burners, roasting furnaces, etc.

which may be mixed with nitrogen peroxid in the usual way. As shown each of the said chambers has an inlet pipe E near the lower chambers is.

end, and the chamber X has an outlet pipe E, at the lower end; such pipe may communicate with a suitable exhaust fan, not shown that will propel the gases to the usual ead chambers.

The apparatus thus far described is shown in my co-pending application Serial No. 372,980, filed May 10th, 1907, and the method utilizing the apparatus is claimed therein. 7

Means are provided whereby either of the concentrating chambers may be supplied with a nitrating material and with a weak acid, such supply conducted alternately to the said chambers, and means are also provided whereby the liquid flowing from either chamber where denitration is efiected is conducted to the top of the other chamber, which in such case constitutes the high concentration chamber, and means are also provided for supplying the intermediate chamber with a cold, weak acid solution, and the liquid from this chamber may be conducted upward by suitable means and mixed with the nitrating medium flowing to either of the concentrating chambers.

As shown there are three tanks T, T T arranged at suitable elevations above all of' the chambers, and one of the said tanks, as the tank T, is supplied through a pipe 3 with nitrous vitriol and has two discharge pipes 4,4, provided with cocks 5,

leading to distributors J, above the concen trating chambers, said 'distributers havthrough the pipe 6 and through the medium of the pump P with liquor from a tank T",

and distributes the said liquor throu h pipes 8, 8, provided with cocks 9, 9, to t e distributers J, while the remaining tank T receives a weak acid, or chamber acid, either through a supply pipe 10 or through a branch 12, leading from a pipe 13, into which liquor passing from the discharge pipe 14 of the intermediate chamber 1s pumped by means of a pump P, said pipe 13 also assing to the tank T, and between the discharge pipe 14 and the pump P' may be arranged a cooler c and a reservoir or tank T.

The dischar ed liquor from each of the concentrating c ambers flows through a pipe or conduit 16, and may pass directly or through a cooler c and plpe 17 to a tank nitrating chamber will be moderately warm T, and the pump P serves to withdraw the liquid from the tank T and pass it on through a pipe 19 to suitable storage tanks. The pipes 17 are also provided with branches 20 leading to the tank T The tank T may discharge its contents into a distributer K, which is above the chamber X and discharges into the latter.

In the operation of the above described apparatus both of the concentrating chambers receive burner gases which pass throu h the same, and one of the chambers X, )5, is fed with a mixture of weak acid and nitrous vitriol at such a rate regulated by the valves 5 that the acid will be discharged at the bottom at the usual strength (60 to 62 Be.). The liquid discharged from this chamber is then elevated through the pipe 6 to the tank T and a portion thereof is discharged, through one of the pipes 8 and distributer .J, into the other chamber where it is concentrated, the action being so regulated that the acid shall be concentrated to 66 Be, or'to any desired greater strength above that which is supplied to this chamber. To obtain this concentrated acid free from nitrogen compounds no nitrating material iii any shape must be admitted to the chamber used for high concentration, the dcnitration being performed .wholly in the other chamber. Therefore the burner gas fine leading to the chamber in which the concentration process is then performed is not supplied with nitrogen oxids. This may be accomplished in various Ways, for instance, by shutting oif the niter ovens through which the burner gases pass or cutting off the supply of the material which produces the nitrogen oxid.

The gases issuing from the top of the deand laden with nitrogen compounds, and passing to'the chamber X. are mixed with the hot gases passing from the other chamber, and are cooled by the discharge of cold, weak acid from the distributer K, and the solution passing downward in the chamber X and discharged therefrom may be pumped by the pump P into either the tank T, to be used in connection with the nitrous vitriol in the denitrating chamber, or into the tank T to be again employed in the intermediate chamber. trating chambers are thus so mixed and cooled in the intermediate chamber that they cannot effect any damage to the lead work.

The above described operations may be performed alternately with the two chamas well as that from the intermediate chamber X is cooled by means of the coolers The gases from the concen 0 0 so as to be reduced to the proper working temperature. 7

In the manufacture of sulfuric acid it has been found that the principal impurities, especially iron, Which are absorbed by the sulfuric acid circulating in the concentrating chambers will be separated and deposited in the said chambers as solid particles if the concentration is carried above approximately 64 Baum. This deposit of the impurities will in time result in so clog ging and obstructing the interstices of the material in the said chambers as to interfere with or prevent further operations, but it has been found that if a weaker solution is passed through thechamber'in whichsuch deposit has occurred the impurities will again be taken up and the chamber thereby cleansed or freed from obstructions.

It will be seen that by first concentrating the acid to a sufficiently high degree to insure the deposit of the impurities, and then discontinuing the high concentration in the chamber where such deposit occurs and bringing the Weak acid into contact with said impurities, I am enabled to remove the deposit and restore the said chamber to its original effective condition While the deposit is taking place in the other chamber, from which it is then removed in like manner, and by thus alternating the action in the two chambers the desired concentration may be I effected with a minimum expenditure of time and labor, all of the chambersbeing continuously in effective operation. Fur- 10o ther by the employment of the intermediate chamber the Warm gases from the denitrating means and the hot gases from the high concentrating means are mingled together and their temperature reduced, and a further 10:, reduction is effected by the supply of cold weak acid, a certain amount of concentrationbeing effected also in the said intermediate chamber. I

Without limiting myself to the precise llo construction and operations above described, I claim as my invention: I

1. In the manufacture and concentration of sulfuric acid, subjecting a weak acid to treatment with hot burner gases in a chamber to concentrate the acid to a degree exceeding 63 Be. and to insure a deposit of the principal impurities, and thereafter treating weaker acid in the same chamber to clear the latter by the solution of the said 12 impurities.

2. In the manufacture and concentration of sulfuric acid, treating a solution of sulfuric acid of less strength than 63 Be. with hot burner gases to concentratethe acid and cause a deposit of impurities, and simulta-v neously treating a. mixture of weak acid and nitrous vitriol with burner gases, to secure a solution of medium strength, and thereafter subjecting the said deposits to the aearw action of the last named solution, to dissolve the same.

3. In the manufacture and concentration of sulfuric acid, treating two solutions of acid independently and simultaneously with two different volumes of hot burner gases, and also denitrating one solution, and concentrating the other to an extent to deposit impurities thereof, and thereafter dissolving the said impurities by the denitrated solution.

4. In the manufacture and concentration of sulfuric acid, treatin two solutions of acid independently and simultaneously with two different volumes of hot burner gases,

and also denitrating one solution, and concentrating the other to anextent to deposit impurities thereof, and thereafter dissolving the said impurities by the denitrated solu tion, and'mlxing together the gases passing from both operations and subjectingthem to the action of cool,.weak acid to cool the same.

5. The method of manufacturing concentrated sulfuric acid which consists 1n exposing a body of the acid to the action of hot gases so as to concentrate. the acid to asufiicient extent to cause the deposit of the impurities thereof, suspending the concentrating process, and removing the impurities by a body of weak acid.

6. The method of manufacturing concentrated sulfuric acid which consists in concentrating a body of the acid in one chamber to an extent suificient to cause the deposit of the impurities thereof, then shifting the acid supply to another chamber and causing the concentrating process to take place therein, and simultaneously removing the impurities in the first chamber by a solvent.

- 7 The method ofmanufacturing concentrated sulfurlc acid which consists in con; eentrating a body of the acid in one chamber to an extent suflicient to cause the deposit I of the impurities thereof and simultaneously causlng a solvent to remove the impurities deposited in another chamber, and then interchanging the 'acid' and the solvent so that the concentration is. carried on in the second chamber while the solvent action is carried on in the. first chamber.

8. The method'of manufacturing concentrated sulfuric acid which consists in exposthereof and simultaneously exposing a weak acid to the action of burner gases in the second chamber, and thereafter interchanging the functions of the chambers so that the concentration is. carried on in the second chamber while the solvent action is carried on in the first chamber.

10. The method of manufacturing concentrated sulfuric acid which consists in conducting burner gases through a denitrating tower supplied with nitrous vitriol and a weak acid, and conductinghot burner gases through a, concentrating tower supplied with acid and causing the concentration in the concentrating-'tower to be carried on to an extent suificient to cause the deposit of the impurities of the acid, and interchangthe deposit of the impurities of the acid,

and interchanging the functions. of the concentratingand denitrating apparatus so that the impurities deposited are dissolved. p12. The method of manufacturing concentrated sulfuric acid which consists in exposing a body of the acid in the concentrating chamber to the action of hot gases to an extent sufficient to cause the deposit of the impurities thereof, and thereafter reducing the concentrating action to an extent sufficient to cause the impurities to be dissolved.

13. The method of manufacturing concentrated sulfuric acid which consists in conducting hot burner gases through a concentrating tower supplied with acid, carrying the concentration to an extent sufficient to cause the deposit of the impurities thereof, and. thereafter reducing the concentrating action of the burner gases to an extent sufficient to cause the impurities to be dissolved.

14. The method of manufacturing concentrated sulfuric acid, which consists in exposing a body of the acid to the action of hot gases so as to concentrate the acid to an extent suflicient to cause the deposit of the impurities thereof, suspending the concentration prbcess and removing the impurities by a body of weak acid in .the presence of hot gases.

15. The method of concentrating sulfuric acid which consists in conducting the burner gases through a concentrating tower supplied with acid, carrying the concentration to an extent suflicient to cause the depositof the impurities thereof, and thereafter removing the impurities with a body of Weak acid.

16. The method of concentrating sulfuric acid which consists in conducting "the burner gases through a concentrating tower supplied with acid, carrying the concentration to an extent sufficient to cause the deposit of the impurities thereof, and thereafter conducting the gases into a cooling apparatus before discharging them into the chambers.

17. The method of manufacturing concentrated sulfuric acid which consists in concentrating a body of the acid in one chamber to an extent sufiicient to cause the deposit of the impurities thereof;-sus ending the process in said chamber,-shift1ng the acid supply to another chamber, and causing the concentration process to take place therein While the lmpurities in the first chamber are removed.

In testimony whereof I afiix my signature in presence of two witnesses.

OTTO PROELSS.

Witnesses W. S. HALL, CHAS. LINDMUELLER. 

